Is it possible to parse websites?

Question

Parsing

I'm going to parse a project for the first time using the phpQuery library, and then the questions arose, is it illegal? Will they suddenly be able to make any claims? Parsing will be about 20'000 pages of one of the top sites.

Answer 1

Good day.
Search engines do the same thing. Just do not create a big load, have a conscience.
But what matters is what you do with that information. Collecting statistics or publishing as if from oneself are completely different things, not to mention any copyrights, etc.

Answer 2

Imagine that you are walking down the street, you are grabbed and a liter of blood is pumped out... are you a donor or a victim? ))
IMHO, a donor is something voluntary and conscious. Everything else is illegal.